I have a question about a possible new iTunesEncode feature (or any other program driving Apple's AAC encoder). Wouldn't it be possible to add a gapless feature? It might sound silly, but after all, nyaochi did it with the latest Fraunhofer MP3 encoder (here and here). I'm not a coding expert -I'm not a coder at all- but I think that doing it wouldn't be an impossible task.

Adding somewhere in the tags the precise offset (constant for Apple's encoder) and calculating the amount of padded sample maybe suffice? I don't really know. faac and Nero AAC are gapless, and apparently Apple is not hurry to implement this feature. It's a pity, because Apple's encoder is pretty good. Gapless playback is not possible on any iPod, but on a computer (playing with foobar2000 as exemple) users would benefits from it.

Could we reproduce Nyaochi's ACMenc patch to work with iTunes? Or make something similar? What do you think?

The specification discusses the gapless playback for at least MP3, AAC, and ALAC by taking an AAC example of encoder delay and the number of samples in a frame. IMHO we should wait for the next major update of iTunes/iPod.